This wasn’t Canadians! Stop telling lies! It was clearly The Joker. Look, he’s even painted the bat-symbol right there! He’s trying to taunt Batman!
Wouldn’t that mean it’s Batman?
When has Batman ever left his own symbol? It’s used by others to summon him.
He puts his symbol everywhere. Like everything he owns is covered/made out of that symbol. Certainly that would be his tag/signature right?